基于实时数字脉冲处理技术的核谱仪研究  

Study of Nuclear Spectrometer Based on Real-time Digital Pulse Process Technique

作　　者：周建斌[1] 胡云川[1,2] 洪旭[1] 陈铁光 陈宝 岳爱忠 何绪新 

机构地区：[1]成都理工大学核技术与自动化工程学院,四川成都610000 [2]山东省科学院海洋仪器仪表研究所山东省海洋环境监测技术重点实验室,山东青岛266001 [3]成都中核高通同位素股份有限公司,四川成都610041 [4]中国石油集团测井有限公司,陕西西安710032

出　　处：《原子能科学技术》2015年第12期2272-2276,共5页Atomic Energy Science and Technology

基　　金：863计划资助项目(2012AA061804);国家国际科技合作专项资助(2013DFR90220);山东省科技发展计划项目资助(2015GSF115001)

摘　　要：本文提出一种基于80 MHz ADC的数字化γ能谱系统。系统由探测器、前端电路、ADC和数字处理单元组成。数字处理在FPGA中完成,主要包括FIR数字滤波、脉冲梯形成形、幅度甄别、数据通讯。为减小高速ADC在采集过程中引入的噪声信号,在数字处理单元实现FIR数字滤波,对数字脉冲信号先进行滤波处理,再进行脉冲梯形成形,得到高分辨率的能谱数据。测量系统中模拟信号全部采用直流耦合,数字脉冲宽度为1.6μs,对137 Cs的能量分辨率达6.88%。A digital gamma ray spectrometer based on 80 MHz ADC was presented.The system consists of NaI（Tl）detector,front-end circuitry,80 MHz ADC and digital pulse process（DPP）unit.The FIR digital filtering,pulse trapezoidal shaping,pulse height discrimination and data communication were implemented in DPP.The pulse trapezoidal shaping algorithm was applied to obtain good energy resolution and throughout.In order to reduce the influence of noise introducing from the high-speed ADC,the FIR digital filter was employed.The digital signal coming from ADC was smoothed by FIRfilter firstly,and then shaped as trapezoidal pulse for further processing.The analog signal was coupled by DC,and the digital pulse width is 1.6μs.The results show that the resolution for 137 Cs can reach 6.88%.

关 键 词：核脉冲信号 FIR数字滤波 脉冲梯形成形 80 MHz采样率 

分 类 号：TL822.6[核科学技术—核技术及应用]